Electronic transducer device
AssigneeMicronas GmbH
InventorsMario Motz, Ulrich Theus
Life of this patent
Estimating the term…
Abstract
To detect a fault state due to a line break in power supply lines on the receiving side during the operation of a transducer device, the transducer output voltage is forced to an extreme voltage range by a co-integrated p-channel-depletion-transistor. As a result, the signal detection device can reliably detect the presence of the fault state due to a line break in the supply feed lines.
Claims8
A transducer device that provides a signal output, and is connected to a ground conductor and to a voltage conductor, said transducer device comprising:
- a fault alarm circuit that forces a prescribed potential at said signal output through a first p-channel-depletion-transistor situated in an n-well of a p-conducting substrate, when there is a break in the ground conductor, said n-well of said p-channel-depletion-transistor is connected to said operating voltage connection via a first resistor,
- a gate connection of said p-channel-depletion-transistor is coupled to and controlled by a charge pump, which is situated between the operating voltage connection and the ground connection, and
- in a normal operating state, the output voltage of said charge pump is sufficiently high to block said p-channel-depletion-transistor, whereas, if the ground conductor has a break, said p-channel-depletion-transistor conducts and pulls said signal output approximately to the operating voltage to protect said transducer device, wherein said signal output is connected to the ground connection through a second resistor.
A transducer device that provides a signal output, and when there is a break in either a first or second power supply line of said transducer device, said device forces a prescribed potential at said signal output, said transducer device comprising:
- a fault alarm circuit that includes a p-channel-depletion-transistor, which is situated in an n-well of a p-conducting substrate, and which is coupled to the first and second power supply lines and to the signal output,
- said n-well of said p-channel-depletion-transistor is connected to the first power supply line through a first integrated resistor,
- a gate connection of said p-channel-depletion-transistor is controlled by a charge pump, which is situated between the first power supply line and the second power supply line, and
- in normal operation, the output voltage of said charge pump is sufficiently high to block the p-channel-depletion-transistor, whereas, in the case of a disconnection of either the first or second power supply lines, said charge pump can no longer block said p-channel-depletion-transistor, as a result of which said transistor provides said signal output at a value approaching the value of the first or second power supply line still connected to the device, wherein said signal output is connected to said second power supply line through a second resistor.
Dependencies are inferred from the claim text.